Re: [Boost-users] [iterators][range][rangeex] range concatenation

Subject: Re: [Boost-users] [iterators][range][rangeex] range concatenation
From: er (erwann.rogard_at_[hidden])
Date: 2010-01-09 08:13:57

er wrote:

> I am wondering if perhaps someone responsible for range_ex has 
> implemented concat and would care to kindly share it (apparently it's 
> not included in the vault).
> 

Someone tells me I overlooked chain which works similarly, albeit for 
single pass only. Very useful, thanks!

#include <iostream>
#include <vector>
#include <list>
#include <iterator>
#include <algorithm>
#include <boost/range.hpp>
#include <boost/range/chain.hpp>
#include <boost/typeof/typeof.hpp>
#include <boost/next_prior.hpp>

int main (int argc, char * const argv[]) {

        typedef double val_;
     typedef std::vector<val_> vec_;
     typedef std::list<val_> list_;

        vec_ 	seq0; seq0.push_back(1);
        list_ 	seq1; seq1.push_back(2);
        vec_ 	seq2; seq2.push_back(3); seq2.push_back(4);
        vec_ 	seq3; seq2.push_back(5);

        BOOST_AUTO(
             chained,
         boost::chain(seq0,
                 boost::chain(seq1,
                     boost::chain(seq2,seq3)
             )
         )
     );
        
        BOOST_ASSERT( *boost::begin(chained) == 1 ); // Warning : reference to 
temporary
        BOOST_ASSERT( *boost::next(boost::begin(chained),1) == 2);
        BOOST_ASSERT( *boost::next(boost::begin(chained),2) == 3);
        BOOST_ASSERT( *boost::next(boost::begin(chained),3) == 4);
        BOOST_ASSERT( *boost::next(boost::begin(chained),4) == 5);

        std::copy(
             boost::begin(chained),
         boost::end(chained),
         std::ostream_iterator<val_>(std::cout, " ")
     );

     return 0;
}